Telephone system



May 16, 1933. 'BARNAY 1,909,087

' TELEPHONE SYSTEM Filed Oct. 9, 1931 4 Sheets-Sheet l Fig/ 323 Inuenlnr HrTlETi-TE BETFIEH May 16, 1933. A, BARNAY 1,909,087

TELEPHONE SYSTEM Filed Oct. 9, 1931 4 Sheets-Sheet 2 I I I 8 f l I I 808 I A I I j I I l I AT Ii l I. I i 1m? fiTfifiE Bgrnag May 16, 1933. BARNAY 1,909,087

TELEPHONE SYSTEM 4 Sheets-Sheet 5 Filed 001:. 9,

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n -1- g l S 7 Inuanzur Hnlcma kw Patented May 16,1933

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The present invention relates to telephone systems employi automatic switches for I extending connections; one 'objectof the invention relates to the improvement of telephone systems in which conversation switches are set under the. control of marking switches.

According to one feature of the invention I control apparatus common to a pluralit of conversation switches includes a mar ing switch adapted to control. the setting of'any of the associated switches and also adapted to control the setting of a subsequent conversation switch.

' When calls'are to be set up betweentwo exchanges it is often desirable to arrange that when all the junctions for setting up a connection between the two exchanges are busy, a connection can be set up between these ex- .changes over an alternative route.

According to another feature of the invention, a selector switch having access to direct junctions to another exchange and to junctions to a tandem exchange is adapted to be controlled so as to hunt for an idle direct junction to the wanted exchange and when all the direct junctions are busy to continue its hunting operation 'intothe group of junctions. to the tandem exchange.

According to a further feature of the invention, connections out oing from a first exchange to a second exc ange are arranged to be set up over a conversation switch at the first exchange controlled by a marking switch to select a direct junction to the second ex'.

change when an idle junction is available and to select a junction to a tandem exchange when no direct junction is available.

In multi-exchange areas use is often made of register translators and by their usere routing facilities can be readily provided as one or more of the digits transmitted by the calling subscriber can be registered and translated into routing digits which may diffor in number and/or value from those registered.

Such translating arrangements, however.

are generally complicatedand expensive so that any modification whereby the number of translators to be provided may be reduced or whereby they may be simplified would result in a considerable reduction in the cost both of the initial installation of the system and of its subsequent" operation.

According to another feature of the in- -vention in atelephone system in which certain inter-exchange connections are arran to be extended from one exchange to anot er either over direct junctions or over junctions passing through a tandem exchange, the extension of a connection over a direct junction takes place without translation while the extension of a connection throu h the tandem exchan takes place under t e control of translate digits.

According to a further feature of the invention, in a telephone system including main registercontrollers ada ted to control the operation in succession 0 automatic switches,

auxiliary register controllers associated with groups of switches subsequent to the group with which the main r ister controllers are associated are arrange stances to control the extension of a connection independently of the main register controller, t 0 control of which is meanwhile sus nded.

y this arrangement the translating devices can be eliminated from the main register controllers, which can consequently be made very sim le. The auxiliary register cont-rollers nee only be introduced at the particular switching stages at which they are required and then can be made very simple since it is only necessary for them to register a single digit which is then translated to s provide the additional one or more additional stages of selection required.

in certain circum-,

' The invention will be better understood from the following description of one method of carrying the invention into effect taken in in thick lines to indicate that they carry the speech currents during conversation over a completed connection.

Fig. 2 shows control apparatus which is common to a group of selectors similar to the selector of Fig. 1. This common apparatus is arranged to use the received digit twice when it has a particular value or values, first- 1y to control the setting of an associated selector by a marking operation and secondl to control the setting of a subsequent switc by the transmission of a train of impulses, the number of impulses transmitted being the complement of the number received with respect to 11. v

Fig. 3 shows another arrangement of control apparatus for use in common to a group of selectors such as that shown in Fig. 1. The second use of the received digit in this case is efiected by the transmission of a train of impulses in which the number of impulses transmitted is e ual to the number of impulses in the receive digit.

Fig. 4 shows a further arrangement of control apparatus for use in common to a group of selectors such as that shown in Fig. 1. The second use of the receiver digit in this case is effected by the transmission of one or more trains of impulses, the number of impulses in each train being any desired num- Fig. 5 shows a telephone network comprising three exchanges connected together in the form of a triangle.

Fig. 6 shows schematically the trunk lines between the exchanges of Fig. 5.

Fig. 7 shows a subscribers station A, a line switch P, relay group G, a first selector S having access to the selectors of Fig. 1, and a register sender RS arranged to be temporarily associated with the switches employed in the connection.

Each set of control apparatus (Figs. 2, 3 and 4) comprises a rotary switch with eleven positions, the wipers of which are indicated by the letters a, b, 0, cl, 6, 7. These wipers have four arms arranged so that when one arm leaves the eleventh contact the next arm will engage the first contact, a separate arm is accordingly effective in eachquarter revolution; the reference letters given to a wiper are followed by a roman numeral indicating which arm of the wiper in question is being operates and at 404 connects earth to the release trunk conductor over which succeeding switches will be held. Relay 401 energizes over its upper winding when earth is connected to the release trunk conductor over contact 405 which is opened when the first selector moves oil-normal. Relay 401 looks operated over its lower winding and armature 407 to battery connected to the upper speaking conductor of the selector S and closes at 406 the circuit of the holding relay 427 of the register sender. The impulses transmitted by the calling subscriber are repeated by relay 402 and retransmitted to the register over conductor 1E in known manner where they are received by register switches (not shown). These impulses are then sent to the various selectors employed in setting up the connection. Assuming that the selector S has been set and that the connection has been extended to the selector S, Fig. 1, over conductors 300, 301, 302, the register sender is then in a position to transmit the digit for setting the selector S of Fig. 1. Relay 31 of the selector S and relay 11 of the control switch, Fig. 2, energize in series from battery, upper winding of relay 11, common conductor 342, relay 31, armature 322, line conductor 300, armature 407, lower winding of relay 401, to earth. Relay 31, on energizing, completes an operative connection between the conver sation switch and the control switch.

.Relay-ll, on energizing, closes a circuit for relay 14 from earth, armature 112, wiper 0 in normal position, lower winding of relay 14 to battery, and at armature115 disconnects battery from common conductor 341, to which it was connected over wiper a in normal position and resistance 143, in order to mark busy the conversation switches associated with the control switch.

Relay 14 on energizing at 141 opens a point in the circuit of relay 12, at 142 opens a contact in the stepping circuit of the magnet of the switch S, at 142 prepares a holding circuit for itself and at 141 closes a circuit as follows :earth, 141, relay 13, common conductor 345, armature 311, line conductor 301, armatures 408, 409 and 410, relay 411 to battery.

Due to the high resistance .of relay 411, relay 13 is not energized but relay 411 energizes and closes a circuit from earth,wiper cm and normal contact of the counting switch CS, 412 and 413, relay 414 to battery. Relay 414 operates and locks itself over 422 and 423, and at 416 connects the interrupter 11, whose speed is approximately 10 revolutions per second, to the upper winding of relay 415 which under these conditions operates armature 417 only. When the interrupter ceases to make. contact, the lower winding of relay 415 is no longer short-circuited and all the armatures of this relay are operated. The in- Ill terrupter I1 is thereupon connected over i Fi 2, which-thus receives the successive im- Magnet 419 causes the wipers of the switch CS to advance one step each time it is deenergized. When the wiperab finds the contact such as 421 which has been connected to earth by the register switch which corresponds to the digit; being transmitted to the selector S, relay 422 energizes, at 409 stops the transmission of impulses to the selector and at 413 opens the circuit of relay. 414. Relay 414 de-energizes'. and at 424 opens a circuit which controls the de ndence of the switch CS on the various register switches so as to place the switch CS under the control of the following digit. Relay 414 closes at 425 the homing circuit of the switch GS over wiper aa and at 410 again connects relay 411 to the impulsing lead when relay 422 falls away after the wipers of CS leave the position to which they have been set. The register is then in readiness to transmit the next digit, the transmission of which is initiated by the energization of relay 411 which takes place when the impulsing lead has been contion, the energizing-circuit of relay 14 is opened, but this relay remains energized from earth, wiper 0 out 0 its normal position, 152,

- 142, 114, upper winding of 14, resistance 142,

to battery. Each time relay 13 falls away, the upper winding of 14'is short-circuited by earth, 112 and 131 but it does not fall away during the series of impulses owing to the .fact that it is made slow by being shortcircuited. At the end of the series of impulsesrelay 13 remains normal and after an interval relay 14falls away.

Relay 14 on falling away at 141 disconnects the earth from line conductor 301, which holds up the transmission of succeeding digits from the register sender, at 141 connects the test relay 12 to the control lead of the required group of lines from earth, 141, both windings of 12 in series, wiper a and the control lead 348, assuming that the control switch has received five impulses. The rotary circuit of the selector is closed from earth, wiper 0 out of its normal position, 152, 142, 121, 111, common conductor 340, 313, 325, 327, magnet 328, to battery Magnet 328 operates intermittently'to advance the wipers 330333 over the bank contacts When the contacts of a free line in the marked group are encountered by the wi rs such as contacts 334-337, relay12 whic is connected to earth and also connected to the contact "337. 315, wiper 332 on contact 336, conductor 352, contact 115' in the succeeding selector, wiper a resistance 143' to battery, Relay 12 upon energizing at 121 opens the i circuit of magnet 328 to arrest the wipers on the idle selector and at 122 shunts its high resistance upper winding with the low resistance lower winding of relay 11; if there is only a single selector engaging the succeeding selector and its control switch, relay 12 remains held over-its upper winding and rela 11 falls away as the action of its twowin ings are equal and opposite in these conditions. If two selectors attempt to seize the same selector or the same. control switch through two difl'erent selectors, the relays 12 in two selectors shunt one another and in this condition the relays 12 cannot hold over their low resistance windings, one at least of the 1 control lead 348 energizes over wiper 333 on relays falls away and causes the correspond ing selector to advance on to the following contacts by closing 121. In the same way, the current passing through the lower winding of relay 11 isnot suflicient in this condition to make 11 fall away. v

When relay 11 falls away, the circuit of relay'15 is closed from earth, wiper a, 152, 142, 121, 113, wiper b on the fifth contact in its bank, relay 15, common conductor 344,

317, wiper 330 on contact 334, to battery,

through the relays in the seized selector and the control switch such as relays 31 and 11, Fig. 1.

Relay 15 energizes in series with the relays I of the selector and control switch, closes a holding circuit for itself to earth at 151, at 152 opens its initial energizing circuit, at 153 connects'earth to wiper 332 over common-conductor 343 and 314, so as to busy the seized selector and at 154 connects relay 18 to wiper 331 from battery, relay 18, 17 2,154, common conductor 346, 312, and wiper 331.

As soon as relay 14 in the control switch of the selector which has been seized energizes, it connects 'earth to the line conductor 351, as has been described in connection with conductor 301, and relay 18 energizes. Owing to the resistance of relay 18', relay '13 of the seized control switch does not energize. Relay 18 on energizing at 181 connects the impulse cam 185 to relay 16 from earth, cam 185, wiper at out of its normal position, 171 and 181'. Relay 16 energizes upon the first closure of 185 and at 161 prepares its holding circuit in series with relay 17, but this circuit does not come into operation until the impulse cam opens. When the cam 185 opens, relay 17 energizes in series with 16 from battery, relay 16, relay 17, 161, 151, to earth, at 172 opens the circuit of relay 18, at 171 connects the cam 'to' the magnet 10, and at 172'prepares the cirbattery, resistance 10,3, 102, 172, 154, common conductor 346,- 312, wiper 331 on.

contact 335, line conductor 351, contact in the seized selector such as 311, common conductor such as 345, impulse relay of the seized control switch such as 13, contact such as 141 to earth. For each impulse received the control switch advances lts wipers one step in the manner described in connection with Fig. 2. At the end of the sixth impulse, the wipers of the control switch arrive at their normal position, whereupon the circuit of the cam 185 is opened at wiper d and the impulses cease. The control switch of the succeeding selector has been set to its sixth position and, whenthe impulses cease, controls the setting of the selector on to an idle line in the marked group.

When wiper b of the control switch of Fig. 2 returns to its normal position, the cir cuit of relay 32 of the selector is closed from earth, 151, wiper b in its normal position, common conductor 347, 316, relay 32 to battery. Relay 32 upon energizing at 323 closes its holding circuit to earth on the test conductor 302, at 324 connectsearth to contact 336, at 321 and 326 connects the calling line to wipers 330 and 331 and 322 opens the circuit of relays 31 and 11. Contact 321 is closed before 322 is opened, in order to keep the holding relay 401 of the group of feeding relays G energized.

Relay 31 in falling away disconnects the selector from the control switch. Relay 15 falls away when its circuit is opened at 317 and at 151 opens the holding circuit of relays 16 and 17 which fall away. Relay 11 on falling away, at 111 closes the release circuit of magnet 10 but this circuit is without effect in this case as the wipers have already returned to their normal position. At 115 the test circuit of the control switch is closed,

and it can be taken into use on a. fresh call. I When the succeeding selector has been set it seizes in its turn another similar selector and the control switch associated therewith. The circuit of the lower speaking conductor 301 is thus extended by contact 326 and wiper 331 to said control switch where it is connected to earththrough a relay such as 13. This causes relay 411 to energize and .the transmission of the following digit by the register, which has hitherto been held up,

-sender by'o ening the circuit of holding relay 427 an at 407 and 408 closes points the speaking circuit.

At the end of the conversation when the release .of the connection is effected, earth is disconnected from the test conductor 302. This causes the release of relay 32 and the selector is then in readiness to establish an other connection.

If the digit received by the control switch of Fig. 2 does not indicate a direction for which it is necessary to add a train of impulses (the digits 1, 3, 4, 7 and 0 according to the wiring shown) when relay 12 energizes and relay 11 falls away a circuit is completed for relay 32 from earth, wiper 0 out ,of its normal position, 152, 142, 121, 113, wiper b in position 3 for example, common conductor 347, 316 and relay 32. This relay consequently energizes as soon as the selector is set on an idle line of the marked group and effects the release of the control switch without the transmission of a train of complementary impulses.

The purpose of relay 21 of Fig.2 will now be explained; this relay is used when rerouting is to be provided in a network such as that indicated in Fig. 5. In this network the different exchanges are connected together in pairs by groups of auxiliary incoming and outgoing lines, a portion of which is represented in Fig. 6. It is evident that if all the outgoing lines from exchange A to exchange C are engaged it will be possible to reach exchange G by passing through exchange B.

The outgoing lines from exchange A, Fig. 6, towards exchanges B and C terminate in the incoming selectors SAB and SAC. The banks of selectors SAB are connected to the outgoing lines to exchange C as well as to the lines local to exchange B. In a similar manner, there are outgoing lines towards exchange B connected to the banks of selectors SAC, in addition to the lines local to exchange G. The selectors SAB and SAC are arranged to receive one or two call digits; the first digit indicates if the call is for the ex change considered, and in this case the second digit effects the setting of the selector on succeeding a selector at the same exchange. If, on the contrary, the first digit received indicates that the call is for another exchange the selector immediately sets itself on an outgoing line to the exchange indicated.

I In order to obtain these results, the control switches of the selectors which have access to outgoing lines are equipped with a relay such asrelay 21 of Fi 2. Considering the case of exchange A, re ay 21 is wired u in such a manner that its circuit is closed w en all the direct'lines towards exchange B or 6 exchange C are engaged. This circuit can be provided by the use of chain contacts closed when all the lines are engaged, in the manner indicated by contacts 215 and 216.

If, for exam le, the digit indicates the exchange B and the digit 6 the exchange C, then there is a call for exchan e B and there is at least'one idle line outgoing to this exchange, the operation is identical with that previously described and the complementary train of impulses comprising six impulses sent b the control switch pre ares the selector SXB for the rece tion of the following digit which will set S B on a line extending to the following selection stage in the exchange B. If all the lines towards exchan B are engaged, relay 21 is energized by t e closing of 215 andthe control'leads for i 'ts 5 and 6 are connected together at 211. onsequently, the selector will nowhunt for a free line in group 6, that is to say, towards the exchan e C. When a free line terminating in a, se ector SAC is found, the control switch sends the complementary train of impulses comprising six impulses to the selector SAC-which sets its wipers on an outgoing line terminating in the selector SCB in the exchange B, which is set by the following digit of the called number, thus, the connection AB isestablished by passing through exchange C.

For a call from exchange A to exchange C (digit 6) the complement train of impulses comprises five impulses which determine the setting of SAC on 'a selector local to the exchange C. In the same manner, calls from A to G can pass throu h exchange B and thosefrom B to A by those from B to C by A; those from C to A by B, and those from C to B by A, with the employment of the minimum equipment and without complications which could prejudice the successful operation of the network.

In the method of carrying out the invention represented in Fig. 3, the train of impulses transmitted from the control apparatus comprises a number of impulses equal to that received by the control switch. I f

If the control switch, Fig. 2, associated with Fig. 1 is replaced by that shown in Fig. 3, the operation 18. the same (reception of impulses and setting of the selector) until the operation of relay 12 and the release of relay 11. If the received digit is not to be used twice, relay 19 energizes from earth, wiper'c out of its normal ition, 152, 142, 121, 113, wiper b to one 0 .positions 1, 3, 4, 7 or 0 according to the wiring shown, relay 19 to battery. Relay 19 upon energizin closes the circuit of relay 32, from eart '65 192, common conductor 347, 316, relay 32. to

its bank connected to the lead marked by the battery. Relay 82 on energiz' extends the connection to the succeeding :Eactor and effects the release of the control switch in the manner described in connection with Fig. 2. \If the received digit is to be used twice, relay 15 energizes, when relay 12 energizes and relay 11 falls away, and is followed by the energization of relays 18, 16, and 17, the advance of the'wipers by magnet 10 under thecontrol of cam 185 and the transmission of impulses produced thereb in the manner described in connection wit Fig. 2, The circuit of cam 185 includes contact 191 of relay 19, and when wiper c engages the contact in control group, relay 19 energizes from earth 153, common conductor 343, 314, 315, controi wiper on contact 337, control lead 348, according to wiring shown, the tenth bank contact of wiper e, relay 19 to battery. Relay 19 at 191 opens the circuit of the cam 185 in order to arrest the transmission of impulses and closes at 192 the circuit of relay 32in order to extend the connection and to release the control switch. When relay 11 falls away, the circuit of magnet 10 is closed from. cart wiper 0 out of its normal position, 152, 142, 121, 111, 101, magnet 10, battery. Magnet 10 operates intermittently to advance the wipers to their normal position, whereupon the circuit of 10 is opened.

In accordance with the wiring shown in Fig. 3, digits 2, 4, 8 and 9 are used twice and the manner of connectin the corresponding control wires to the han of wiper 6 will be noted. It should be mentioned that for digits greater than 5, the wiper 6 will only engage the earthed contact in the uarter-revolution of the control switch fdllowing that in which the setting of the selector was ef- 1 fected.

In the embodiment shown in Fig; 4, the control switch acts as a sender translator after it has controlled the setting of the selector. If Fi 2 is replaced by Fig. 4, the operation is t e same up to the time when the setting of the selector is terminated. It will first be assumed that the received digit is of such a value that it is not to be used twice, such as digits 1, 2, 4, 6, 8, 9 and 0 ac- '115 cording to the wiring shown. Upon the energization of relay 12 and the release of relay 11, relay 19 energizes in the manner described in connection with Fig. 3, and efl'ects at 192 the energization of relay 32 of the se- 12o lector. Relay 32 on energizin extends the connection to the succeeding se ector and effects the release of the control switch.

If the received digit indicates'tliat it has to'be used twice such as the digits 3, 5 and 7, according to the wiring shown, when relay '12 energizes and relay 11 falls away the c ir-' cuit of, relay 20 is closed from earth, wiperc out'of its normal position, 152142, 121, 113, wiper b in positions 3, 5 or .7, relay 20 to the selector and control switch seized; such as relays 31 and 11 of the selector shown in Fig. 1 and its control switch. Relay 15 on energizing at 151 closes its holding circuit, at 154 prepares the circuit of relay 18. Relay 20 at 153 connects earth to the test wiper 332 at 153, at 204 closes the circuit of magnet 10 from earth, wiper 0 out of its normal position 152, 205, 162, 101, magnet 10 to batter an at 203 closes the holding circuit of re ay 20 in parallel with magnet 10.

Magnet 10 operates intermittently and causes the wipers to advance a quarter of a revolution to the first intermediate normal position. In this position, the circuit of relay 20 and of magnet 10 is opened at wiper 0. Relay 20 on falling away, at 201 prepares the circuit of the cam 185 and when relay 18 energizes in the manner described in connection with Fi 2 the circuit of relay 16 is closed from earth, cam 185 in its closed posi-" tion, 191, 201, 171, 181, relay 16 to battery. Relay 16 on energizing at 161 prepares its holding circuit and at 162 opens a point in the release circuit of magnet 10.

When the cam 185 o ens, relay 17 energizes in series with 16 rom earth, 151, 202, 161, relays 17 and 16 to battery. Relay 17 upon energizing at 172 opens the ClICllit. of relay 18, at 172 prepares the impulsing circuit to the selector; and at 171 connects'the cam to the magnet 10. The succeeding closures of the cam 185 causes the magnet to operate in the following circuit: earth, cam 185, 191, 201', 171, magnet 10 to battery. The magnet causes the wipers to advance and for each step made transmits a battery impulse from resistance 103, 102, 172, 154 and the common conductor 346 to the succeeding selector. V

The secondarm of the wiper 0 now engages its bank contacts whilst arm eIIwhich is the only operative arm on wiper 0 also engages its bank contact. Assuming that the selector is set on group 5, the control wire 348 of group 5 is connected to earth from earth, 153, common conductor 343, 314, 315, control wiper 333 on contact 337 and common conductor 348. This conductor is also connected to the 5th contact in the bank of wiper 611 and the second contact in the bank of wiper d-III, thus after five impulsesthe circuit of relay 20 is closed from earth on wiper 348, wiper e-II on the fifth contact of its bank, relay 20 to battery. Relay 20 on energizing, at 201 opens the circuit of the cam to stop the sending of impulses and at 202 opens the circuit of relays 16 and 17 which fall away.v

When relay 16 falls away, the release circuit of magnet 10 is closed at 162 and the 5 and 2impulses are sent as has magnet causes the wipers to advance to the second intermediate normal position in the manner described for the first intermediate normal position. In the third quarter revolution wiper 0 III and d III engage their bank contacts. When relay 20 falls away due to the opening of its circuit at wiper 0, it again closes the circuit of the cam at 201 and when relay 18 energizes, the second train of impulses is transmitted as will be described.

Since conductor 348 is connected to the second contact of the bank of wi r dIII, after two impulses relay 19 energizes from earth on conductor 348, wiper d III on the second contact of its bank, relay 19 to battery. Relav 19 opens at 191 the circuit of cam 185 to stop the transmission of impulses and closes at 192 the circuit of relay 32 of the selector. Relay 32 on energizing extends the connection to the succeeding selector and effects the release of the control switch.

When the circuit of relay 15 is opened in the selector it falls away and at 151 opens the circuit of relays 16 and 17 and closes the release circuit of magnet 10 from earth, wiper 0, out of its normal osition, 152, 142, 121, 111, 101, magnet 10 to attery. Magnet 10 operates intermittently to advance the wipers to the third intermediate normal position. In the intermediate normal positions the release circuit of 10 is closed from earth, 153, through II, dIII or fIV in normal position, 101, magnet 10 to battery. In the present case, the release circuit extends over fIV and when the wipers leave the third intermediate normal position, the circuit extends over wiper c as described above. In the normal position, the circuit of magnet 10 is opened at wiper c; at wiper a1, battery in series with resistance 143 is connected to the common conductor 341 over 115 in order to allow the control switch to be taken into use for another call.

In accordance with the wirin shown in Fig. 4, upon the reception of igit 3 and afterthe setting of the selector a single train of impulses is sent comprising three impulses. The control wire. of 3 is connected to contact 3 of the upper bank of wiper eII and relay 19 is connected to contact 3 of the lower bank of the same wiper.

For the. digit 5, two trains of im ulses of een described.

For the digit 7, three trains of impulses are sent after the settingof the selector comprising 8, 6 and 9 impulses in accordance with the wiring shown.

It is evident from the preceding that the received digits can be translated in other ways than those shown in Fig. 4. It is only necessary for the wiring to be such that relay 20 energizes to stop the sending for all the trains of impulses exr pt the last, for which relay 19 energizes in order to stop the sendin said marker switch for transmitting a, se-

.ries of impulses over the selected trunk, the -value of said impulse series depending upon the initial setting of the marker switch.

2. In a telephone system, a selector switch groups of other switches accessible to said first switch, a marker switch associated with said first switch, means for setting said marker switch to mark one of said switch groups, means for operating said selector switch to select an idle switch in'the-marked grou and means controlled by the marker switc for positioning the selected switch in accordance withthe marker switch setting.

3. In a telephone system, a plurality of selector switches, groups of trunks accessible to said switches, a marker switch common to said selector switches means for temporarily associating said markerswitch with one of said selector switches, means for setting the marker switch to mark one of said trunk groups, means for operating the associated selector switch to select an idle trunk in the marked group, and means in said marker switch for transmitting a series of impulses over the selected trunk, the value of said impulse seriesdependin'gupon the initial setting of the marker switch.

4. i In a telephone system, a switch, groups of trunks accessible to the switch, a control device associated with the switch, means for setting said device to mark a particular one of said trunk groups andto determine subsequent controlling functions of the device, means for operating the switch to select an idle trunk in the marked group, and means in the device controlled by its initial setting .for transmitting a series of impulses over the selected trunk and for thereafter disconnecting itself from the switch.

5. In a telephone system, a switch, a control device associated with the switch, groups of trunks accessible to the switch, means for setting the device to mark one of said trunk -groups, means for operating the switch to ,select an idletrunk in the marked group,

means for reoperating said device, and means responsive to the reoperation of said device for transmitting a number of impulses over the selected trunk line in accordance with the position taken by said switch in selecting the trunk. I

6. In a .telephone system, a switch, a control device associated with the switch, groups tin I marked position of the device.

7. In a telephone system, a selector switch, groups of trunks accessible to the switch, a control switch associated with said selector switch, means for operatin said control switch step by step to a position corresponding to the position in which a particular one of said trunk groups is accessible to said selector switch, means for o crating said selector switch to select an id one group and to mark a position of said conle trunk in said trol switch, means for restoring the control switch to normal and for reoperatingthesame 'stepby step to said marked osition, and means in the control switch or transmit an impulse over the trunkselectedby sai selector switch responsive to each step taken to reach the marked position.

groups of trunks accessible to said switch, a marker switch associated with said selector switch, mean for setting said switch to mark a wanted group'of trunks, means associated with said marker switch to extend the marking to a second group of trunks responsive to all trunks of the wanted group being busy,

8. In a telephone system, a selector switch,"

and means for operating the selector switch to select an idle trunk in said second group.

9. In a telephone system, a plurality of selector switches, groups of trunks accessible to said switches, a marker switch common to said selector switches, means for temporarily associating said marker switch with oneof said selector switches, means for setting said marker switch to mark a wanted group of trunks, means associated with said marker switch and operative responsive to 7 all trunks of the wanted group being busy for extending the marking to a different group of trunks, andemeans controlled by said marker switch for operating the associated selector switch to select an idle trunk in said difi'erent group.

10. In a telephone system, a first exchange, I

a second exchange, trunklines directly connecting said exchanges, other trunk lines con- 1 meeting said exchanges via a tandem exchange, a selector in said first exchange having access to said trunk lines, a control switch temporarily associated with said selector, means for setting said control switch to mark said first trunk lines, means associated with said control switch for extending said marking to said other trunk lines in case all of said first trunk lines are engaged, and

, means in said control switch for operating said selector to select an idle one of said other trunk lines.

11. In a telephone system, a register controller, switches adapted to be directly controlled bysaid controller, means for setting said controller responsive to a series of digit impulses, means in said controller for positioning any one of said switches in accordance with the setting of the controller, and means in said controller for transmitting a plurality of series of digit impulses through the positioned switch.

12. In a telephone system, a first switch, a control switch associated with said switch, a second switch accessible to said first switch, two groups of trunks accessible to said second switch, means for setting said control switch responsive to either of two digits whereby the control switch is enabled to operate said first switch to connect with said second switch, and means in said control switch dependent upon the setting thereof for determining the particular one of said trunk groups to be selected by said second switch.

13. In a telephone system, three exchanges, trunk lines directly connecting said exchanges, selectors in the first exchange having access to trunks extending to the second and third exchanges, selectors in the second exchange having access to trunks extending to the first and third exchanges, a control switch adapted to be temporarily associated with any one of said selectors in the first exchange, means for setting said control switch to designate a call to the third exchange,

- means controlled by said control switch for operating the associated selector to extend the call over an idle trunk extending to the third exchange provided such trunk is available, and means controlled by said control switch for causing the associated selector to extend the call over an idle trunk extending to the second exchange and for causing one of said selectors at the second exchange to further extend the call over an idle trunk extending from the second to the third exchange when all trunks extending from the h r st to the third exchange are in use.

14. In a telephone system, groups of automatic switches, a register controller associated with the first group of switches and adapted to control the setting of a series of switches in a plurality of said groups to extend a connection, an auxiliary register controller associated with one of said groups of switches subsequent to said first group, and means insaid auxiliary register controller for temporarily suspending the operation of said first register controller and for controlling the setting of switches in certain of said groups independent of said first register controller. 15. A telephone system as claimed in claim groups in operating through the respective positions.

18. A telephone system as claimed in claim 10 in which the control switch is set in response to a digit designating the trunk lines directly connecting the exchanges.

k 19. A telephone system as claimed in claim 10 in which the extension of the marking from the direct connected trunks to the tandem connected trunks is effected by varying the connections in the banks of the control switch,

20. In a telephone system, a trunk terminating inan automatic switch, groups of trunks accessible to said switch, a second switch associated with said first switch,

means for transmitting a series of impulses over the first trunk to set said second switch, means controlled by said second switch in accordance with its setting for causing said first switch to select an idle trunk in a particular one of said groups, and means in said second switch for transmitting over the selected trunk a series of impulses of a value determined by the setting of the switch.

21. In a telephone system, a switch, a con trol device associated with the switch, groups of other switches accessible to the first switch, means for setting the device to mark one of said switch groups, means for operating the switch to select an idle switch in the marked group, means for restoring the device to normal, and means controlled by the device in restoring for positioning said selected switch.

'22. In a telephone system, a plurality of switches, a control device common to said switches, groups of other switches accessible to said first switches, means for temporarily associating said device with one of said first switches, means for setting said device to,

under control of a register controller and in are initially advanced under directive control which the operation of the register controller of a calling party and further advanced auto is temporarily suspended during the restormatically under control of an interrupter.

ing of the control device.

25. In a telephone system, a trunk terminating in an automatic switch, groups of trunks accessible to the switch, a second switch associated with the first switch, means for transmitting a series of impulses over the first trunk to set the second switch, means controlled by the second switch in accordance with its setting for causing the first switch to select an idle trunk in a particular one of said groups, and means in the second switch for transmitting one or more series of impulses over the selected trunk, said series having an arbitrary predetermined relation to the setting of the second switch.

26. A telephone system as claimed in claim 25 in which the value and number of impulse series transmitted over the selected trunk is determined by the position taken by the first switch is operating under control of the second switch.

27. A telephone system as claimed in claim 25 in which the second switch operates as a marking switch to enable the first switch to select a trunk in the proper group and in which the first switch subsequently operates as a marking switch to enable the second switch to transmit one or more impulse series of the proper value over the selected trunk.

. 28. A telephone system as claimed in claim 25 in which the second switch disassociates itself from the first switch following impulse transmission and effects a direct connection between the first trunk and the selected trunk over which additional impulse series are transmitted independent of the second switch.

29. In a telephone system, an automatic switch equipped with wipers, a control device equipped with wipers and associated with said switch, groups of trunk lines terminating in contacts accessible to the wipers of said switch, contacts individual to said trunk groups and accessible to the wipers of said device, means for advancing the wipers of said device step by step to a contact associated with a particular trunk group, means for advancing the wipers of said switch to establish a connection with a set of contacts terminating an idle trunk in said particular group, means for further advancing the wipers of said device step by step to their normal position, and means for transmitting an impulse over the connected trunk line for each further step of the wipers of said device.

30. A telephone system as claimed in claim 29 in which the control device is common to a plurality of switches and is released for other connections responsive to its return to normal position.

31. A telephone system as claimed in claim 29 in which the wipers of the control device In testimony whereof I alfix my signature.

ANTOINE BARNAY. 

